Draftsman&#39;s curve.



No. 629,569. y Patented July 25, |899. C. A. KLINTBERG.

DRAFTSMANS'CURVE.

(Application filed Dec. 30, 1898.) #No Model.)

WIT EEEEE Ng m me nonms Firms PHo'ro-LITHD.. wAsNmGTaN, u. c.

UNITED STATES PATENT OFFICE.

CARL ANTON KLINTBERGQ'OF NWKPING, SWEDEN.

DRAFTSMANS CU RVE.

SPECIFICATION forming part of Letters Patent No. 629,569, dated July 25, 1899.

Application filed December 30, 1898. Serial No. 700,729. (No model.)

To a/ZZ whom t may concern.-

Be it known that I, CARL ANTON KLINT- BERG, a citizen of Sweden, residing at Nowkping, Ostergtland, Sweden, have invented new and useful Improvements in Draftsmens Curves, of which the following is a specification.

My in vention relates to a new and improved adjustable instrument foruse in drawing arcs of circles and irregular curves, of which the following is a specification, reference being had to the accompanying drawings, wherein- Figure l represents a top plan view of the device. Fig. 2 represents a side elevation showing a portion of the curved elastic strap broken away for the clearer representation of the interior adjusting mechanism. Fig. 3 represents a partial interior view of the device, showing means for strengthening the curved elastic strap. Fig. 4 represents a detail side elevation of one of the notched arms, and Fig. 5 represents a modification of the manner of journaling the end of the adjusting-screw relative to the curved elastic strap.

Similar letters refer to similar parts wherever they occur on the diderent parts of the drawings.

The inven tion comprises an elastic stra-pcf metal or other elastic material made up of two or more parts A A A, Figs. l and 2, formed in dilerent curves, bent in different directions, and joined to each other by rivets a a,

Fig. 1, or by solder.

To get a su fticient stiness anywhere where it is necessary, the strap A has a shorter strap D placed on its inside and so joined to it that the strap D can slide or slip along strap A, as shown at d d', Fig. 3. A rod B, Figs. l and 2,screwthreaded throughout the greater portion of its length, is so joined or connected with the elastic strap that the shape of said strap can bev changed by turning the rod. For this purpose one end of the rod B is rotatably mounted in a lug on the strap A, as at g, Figs. l and 2, or in the strap A itself, as shown at g', Fig. 5, and the screw-threaded portion passes through a screw-nut E, rigidly secured between two ends of the strap A. By turning the rodB by means of a thumb-nut O, secured thereon, the different curves may be made to change their forms by bringing opposite ends of the device near together or drawing them farther apart, as will be understood.

The letters F F indicate two arms, the purpose of which is to hold the elastic strap A and to give 'different forms to its curves. These arms have their inner ends pivotally mounted on a screw-nut G, engaging the screw-threaded portion of rod D, and on their under sides are lprovided with a series of notches or recesses, as shown in Fig. 4, any one of which may be made to engage the edge of strap A and prevent the strap from eX- panding or contracting at that point under the operation of rod B, or the strap may be bent by pressure of the hand and held to such position by bringing the arms F into engage` ment with the strap. By turning the screw nut G the arms may be carried to different points on rod B to engage with the strap.

What l claim as my invention is-a l. In an instrument for drawing curves, the combination of an elastic strap, consisting of several connected parts, a rod connecting op posite parts of said strap and having a movable member mounted thereon, and arms pivotally mounted at their inner ends on said movable member and providcdin their edges with a series of notches or recesses for engaging the elastic strap and by means of which the strap can be given different forms of curves,- substantially as described.

2. In an instrument for drawing curves, the combination of an elastic strap, consisting of several connected curved parts, a rod movably connected with one portion of said strap and having a screw-threaded portion, a boss connecting two ends of said strap and having a screw-threaded aperture receiving the screw-threaded portion of said rod, a screwnut working on the screw-threaded portion of said rod, arms pivotally mounted on said screw-nut and having notched or recessed edges for engaging said strap, and means for turning said rod, the combination operating as described.

Iny testimony whereof I have hereunto set my hand in presence of two subscribing wita nesses.

CARL ANTON KLINTBERG.

Witnesses:

OssIAN HUMBLA, VILHELM RoLIN.

It is hereby certified that the residence of the patentee in the grant and in the head of the printed speeoation of Letters Patent N0. 629,569, granted July 25, 1899, upon the application of Carl Anton Klintherg, for an improvement in Draftsmens Curves, was erroneously Written and printed Novvkping, Sweden, Whereas said residence should have been Written and printed Norrkping, Sweden; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the ease in the Patent Ofoe.

Signed, countersigned, and sealed this 8th day of August, A. D., 1899.

[SEAL] VEBSTER DAVIS,

Assistant Seoretcwyof the Interior.

Countersigned A. P. GREELEY,

Acting Commissioner of Patents. 

